/**
* <summary>This is called whenever there is a disconnect or a connect, the
* idea is to determine if there is a new left or right node, if there is and
* here is a pre-existing transfer, we must interupt it, and start a new
* transfer.</summary>
* <remarks>The possible scenarios where this would be active:
* - no change on left
* - new left node with no previous node (from disc or new node)
* - left disconnect and new left ready
* - left disconnect and no one ready
* - no change on right
* - new right node with no previous node (from disc or new node)
* - right disconnect and new right ready
* - right disconnect and no one ready
* </remarks>
* <param name="o">Unimportant</param>
* <param name="eargs">Contains the ConnectionEventArgs, which lets us know
* if this was a Structured Connection change and if it is, we should check
* the state of the system to see if we have a new left or right neighbor.
* </param>
*/
protected void ConnectionHandler(object o, EventArgs eargs)
{
if (!_online)
{
return;
}
ConnectionEventArgs cargs = eargs as ConnectionEventArgs;
Connection old_con = cargs.Connection;
//first make sure that it is a new StructuredConnection
if (old_con.MainType != ConnectionType.Structured)
{
return;
}
lock (_transfer_sync) {
if (!_online)
{
return;
}
ConnectionTable tab = _node.ConnectionTable;
Connection lc = null, rc = null;
try {
lc = tab.GetLeftStructuredNeighborOf((AHAddress)_node.Address);
}
catch (Exception) {}
try {
rc = tab.GetRightStructuredNeighborOf((AHAddress)_node.Address);
}
catch (Exception) {}
if (lc != null)
{
if (lc.Address != _left_addr)
{
if (_left_transfer_state != null)
{
_left_transfer_state.Interrupt();
_left_transfer_state = null;
}
_left_addr = lc.Address;
if (Count > 0)
{
_left_transfer_state = new TransferState(lc, this);
}
}
}
else if (_left_addr != null)
{
if (_left_transfer_state != null)
{
_left_transfer_state.Interrupt();
_left_transfer_state = null;
}
_left_addr = null;
}
if (rc != null)
{
if (rc.Address != _right_addr)
{
if (_right_transfer_state != null)
{
_right_transfer_state.Interrupt();
_right_transfer_state = null;
}
_right_addr = rc.Address;
if (Count > 0)
{
_right_transfer_state = new TransferState(rc, this);
}
}
}
else if (_right_addr != null)
{
if (_right_transfer_state != null)
{
_right_transfer_state.Interrupt();
_right_transfer_state = null;
}
_right_addr = null;
}
}
}
